In total we're talking about a bit more than 350 buttons with their corresponding sounds. You just have to open the app and tap on the screen, though you can also create a widget using any of the buttons in order to put them directly on the desktop of your Android device.
Instant Buttons is without a doubt the best 'sound button' app that you will find for Android operating systems. Not only does it offer a crazy amount of sounds, but it also offers features like a system of favorites that make it even easier to use.
Requires Android 2.3 or later